Automatic feed for paper box wrapping machines



' y 1959 cs. H. SNYDER, JR ,3

AUTOMATIC FEED FOR PAPER BOX WRAPPING MACHINES- Filed Oct. 31, 1956 3 Sheets-Sheet l INVENTORY- HOWARD SNYDER,JR

1 ATTYSL July 28, 1959 AUTOMATIC Filed Oct. 51, 1956 cs. H. SNYDER, JR Z,86,521

FEED FOR PAPER BOX WRAPPING MACHINES 5 Sheets-Sheet 2 INVENTDRZ GEORGE HOWARD SNYDER,JR.

ATTYS.

Juiy 28, 1959 G. H. SNYDER, JR 2,896,521

- AUTOMATIC FEED FOR PAPER BOX WRAPPING MACHINES Filed 001:. 51, 19 56 3 Sheets-Sheet 5 mvzrq'ron GEORGE HOWARD SNYDER, JR.

I-BY WW AT'TYS AUTOMATIC FEED FOR PAPER BOX WRAPPING MACHINES Application October 31, 1956, Serial No. 619,447

3 Claims. (Cl. 9354) The present invention relates to feeds for paper box wrapping machines, and has particular utility in conjunction with a machine which adheres a gummed wrapper about the interior and exterior side walls of an open-topped box.

Wrapping machines of the stated type are widely used in the industry which are adapted to receive between a pair of wrapping form blocks an open-topped box which is adhered centrally to a gummed wrap. The wrap has side flaps extending outwardly beyond the box which the machine subsequently wraps about the exterior and interior side walls of the box. The wraps with the box spotted thereon are advanced to a point adjacent the wrapping machine by a foraminous or perforated conveyor belt which travels over suction boxes which apply suction to the under surface of the wrap to retain the same in place on the conveyor belt. For many years, the wraps and boxes were transferred manually by an operator from the perforated conveyor into position between the forming blocks of the wrapping machine. In the conventional wrapping machine, the forming blocks carrying the box with wrap adhesively secured thereto, travel from the feeding position downwardly into the body of the machine, where the wrap is secured to the box in well known manner. The box is returned to the feed position at the termination of the cycle when it is automatically ejected from the machine. When manually feeding the wrapping machine, it is operated intermittently, one cycle at a time by a foot treadle under control of the operator. At the completion of each cycle, the operator loads a wrap and box between the wrapping form blocks and manually initiates the succeeding cycle. It is apparent that the speed of operation of the conventional wrapping machine is dependent upon the skill of the operator, and that the operation of the machine is dangerous because of the opportunity for the operator to catch her fingers between the wrapping form blocks.

In order to increase the production of the wrapping machine, automatic mechanical feed devices have been applied to the machine Such feed devices consist of a carrier driven by mechanical linkage from the wrapping machine to reciprocate the carrier between the conveyor and the feed station intermediate the wrapping form blocks. Since the operator at this station is omitted, the control of the wrapping machine is now vested in an operator engaged in spotting the boxes on the wraps at a point along the conveyor well in advance of the wrapper-feed unit. The treadle attachment to the wrapper is now under control of the spotter who permits continuous or intermittent cyclic operation of the wrapper and feeder at her discretion.

Since spotting is a faster as well as less hazardous operation than manual feeding, an increase in the productivity of the wrapper out-put results when the wrapper is automatically fed.

However, conventional automatic feed attachments to the wrapping machine which are mechanically driven by atent the machine, have limitations not present in the subject invention. The above-mentioned mechanical connections are inherently tied in with the cyclic operation of the parent machine. Many of the wrapping machines have very little or no dwell of the form blocks in their opened or box-receiving position. Consequently, the time allotted for placing a new box between the form blocks after the ejection of a previously wrapped one, is of very short duration. However, during this brief interval, the carrier must leave its home position in registry with the form, move to the conveyor, pick up a box, and return to the home position before the downwardly moving form is displaced into position to engage the box. The mechanical movements of the prior art for accomplishing traversal of the carrier consume too much of the allotted time interval. Any delay caused by this, limits the height and width of a box that a machine may process, and hence the utility of the wrapping machine is limited, since the relative distance between the upper form block and the top edges of an incoming box at the time of the carriers return to the home position is a critical and determining factor. The utility of an automatic feeding device is directly related to the .speed with which it can effect the transfer.

With the foregoing in mind, the present invention contemplates an automatic feed attachment for box wrapping machines which overcomes the disadvantages of existing devices outlined above, and moreover, is capable of effecting a substantial increase in the productivity of the wrapping machine without modification of the wrapping machine per se.

More specifically, the present invention provides a pneumatically driven feed mechanism wherein the prime mover for the carrier is independent of any mechanical tie with the wrapping machine. By this arrangement, immediate and independent response of the feed mechanism is obtained; the periods of operation thereof are I controlled by a timing circuit which triggers the operation of the unit in timed relation to the cyclic operation of the wrapper.

In accordance with the invention, since faster opera tion of the carrier is possible under control of the air cylinder, the range of box sizes with regard to the dimensions of height and width, is automatically increased for the reasons outlined above, and the productivity of the wrapper greatly increased.

Another object of the present invention is to provide improved electrical controls for the operation of the pneumatic drive of the feed device.

Another object of the present invention is to provide eifective utilization of the exhaust fluid of the pneumatic drive to assist in the transfer of the wraps and boxes from the conveyor into position intermediate the wrapping form blocks.

Still another object of the present invention is to provide a feeding device of simplified mechanical design which is fully effective in operation and use.

All of the objects and the various features and details of the construction and operation of the invention are more fully set forth hereinafter with reference to the accompanying drawings in which:

Fig. 1 is a plan view of automatic feed mechanism made in accordance with the present invention;

Fig. 2 is a fragmentary view in front elevation of the mechanism shown in Fig. 1;

3 Fig. 5 is a schematic view of the pneumatic and electrical circuits embodied in the mechanism.

The invention provides improved means for feeding wraps'andboxes from'a conveyor into position between "the wrapping form bloc'ks of a wrappingmachine. As

shown in Fig. 1, the wraps W with box B spotted" thereon, are conveyed to the feed stations of the'wrapping machine by a foraminous or perforated conveyor '10. At the feed station, the conveyor overlies a suction box '11 which provides suction through the foraminous conveyor'ltl on the undersurface of the wrap W (see Fig. 3). To insure proper positioning of the box and wrap atthe feed stations of the wrappi'ng'machine, a side guide '12 engages the side'ofthe'box as it enters the feed station and laterally positions the box in flush engagement with a-side stop 13. Longitudinal positioning of the box is provided by an'end stop 14 which arrests 'thetravel of the box and wrap in proper position. The side guide 12, the side stop 13, and the endstop 14 are adjustable on the framework of the feed mechanism in conventional manner to accommodate boxes 'of different sizes, as indicated at 12', 13', and 14 respectively.

From the feed station, the wrapper W and box B are carried into position between the upper and middle wrapping form blocks 17 and 18 respectively of the wrapping machine 19. The form blocks 17 and 18 are driven by a power-driven-main shaft 20 of the machine 19 in conventional manner and cooperate with a lower wrapping form block to wipe the outwardly projecting flaps F of the wrap W against the exterior and interior faces of the side walls of the box B. A carrier is provided to engage the boxes at the feed station and carry the boxes and attached wrap into position intermediate the blocks 17 and 18 of the wrapping machine 19. The carrier is normally positioned in registry with the blocks and is displaced outwardly into engagement with the box at the feeding station and immediately returned with the box and wrap into registr with the blocks 17 and 18.

The carrier comprises a pair of spaced carrier arms 26, 26 having shoulders or latches 27, 27 at their leading end to engage behind the remote side walls of the box B at the loading station. The arms 26, 26 are biased toward one another to frictionally grip the box therebetween and support the same and the attached wrap during its travel from the feeding station into registry between the blocks 17 and 18. The arms are mounted on a carriage 31 slidable on guide rods 32, 32 suspended in the framework -15. Safety stops 35, 35 are provided at opposite ends of the guide rods 32, 32 in conventional manner. The arms 26, 26 are mounted on the carriage 31 by a plate 37 and a cross arm 29. Lateral adjustment of the arms to compensate for differing sizesof boxes -is accomplished by set-screws 28, 28 and longitudinal adjustment of the arms to accommodate different box sizes is accomplished by the slotted connection 38 of the plate with the carriage 31. The carriage is reciprocated along the guide rods 32, 32 by a carriage arm 40 pivoted to the framework 15 as indicated at 41. Vertical support is provided for the arm 40 by a wear plate 42 underlying the arm 40 and secured to the framework 15 as indicated at 43.

In accordance with the invention, the arm 40 is oscillated by pneumatic drive means, in the present instance, an air cylinder 45. As shown in Fig. 1, the piston rod 48 of the cylinder 45 is pivotally secured to the carriage arm 40 as indicated at 46 and the cylinder in turn is pivoted tothe framework by a linkage as shown at 47. The air cylinder 45 through its piston 43 effects reciprocation of the carriage from the extended position shown in Fig. l to a retracted position, indicated by broken.

lines and back to the extended position.

The cylinder has aconstant throw so that the sweep of the carriage arm 401s constant, and its pivot 46 in the arm is adjustable 'by means of the slot 5h, so as to reciprocate the carriage the precise linear distance between the center line of the wrapping form blocks 17 and 18 and the box pick-up position on the conveyor. Once established at installation, this adjustment remains set, and the stops 35, 35 faced with hard rubber pads on their contact faces, are adjusted to constitute cushioning elements at the extreme ends of the carriage travel, and to assist in accurately determining the indexing positions of the carriage. Since the cylinder is of a well known commercial type having a cushioned stroke in either direction, the stops are never subjected to the full thrust of the cylinder. i

The adjustable pivot 47 is used to position the cylinder relative to the piston contained therein after the above noted adjustments are made. By this arrangement, the cylinder may be centered independently of the piston, thus assuring that the piston travel is the same in either direction. In this manner, full cushioning of the stroke by the cylinder is obtained and transmission of' piston shock to the 'frame is avoided. A lock nut 52 is used to secure this adjustment. The cylinder 45 is controlled by a solenoid valve 55 mounted at the rear end of the cylinder 45 and, in turn, controlled by electrical connections operated by the main drive shaft 20 of the wrapping machine. As shown in Fig. 5, the solenoid valve 55 is biased to a position affording admission of pneumatic fluid from the supply to the rear end of the cylinder 45. The fluid flows through a supply conduit 56, a filter 57,- a regulating valve 58, an oiler 59 to the valve 55, and an indicator is provided at 60 (see Fig. 2) fluid supplied to the valve 55. The normal position of the valve also opens the forward end of the cylinder 45 to an exhaust conduit 61. With the elements in the pos'itionshown in Fig. 5, the carriage 31 is in its forward limit position to dispose the arms 26, 26 in registry with the wrapping form blocks 17 and 13. Upon completion of a wrapping operation and ejection of the wrappedbox from the wrapping machine 19, the valve 55 is operated to retract the piston 48 and displace the carriage 31 to ward its opposite limit position. To this end, the drive shaft 20 is provided with a cam 62 operating upon a normally open switch 63 which upon closure completes a circuit through a normally closed limit switch 64 to the coil of a relay 65 having valve contacts 66 and holdmg contacts 67.

Energization of the relay 65 closes the contacts 66 to energize the solenoid 68 of the solenoid valve 55 and there to displace the valve to its opposite limit position admitting pressure fluid to the forward end of the cylinder 45 and opening the rearward end of the cylinder to the exhaust conduit 61. Closure of the holding contacts 67 completes a circuit bypassing the switch 63 to maintain the relay 65 energized. Upon retraction of the piston 48 to its rearward limit position, the carriage arm :40 engages the limit switch 64 thereby opening the same and de-energizing the coil of the relay65. The contacts 66 and 67 open, opening the circuit to the solenoid 68 of the valve 55 and permitting return ofthe valve to its illustrated position in Fig. 5. This eifects operation of the piston rod 48 to return the carriage 31 to its home position illustrated in Fig. 1.

Thus, the present invention provides a novel electrically controlled pneumatic drive for the carriage arm 40 which effects a rapid extension and retraction of the arms 26, 26 from and to their home position in registry with the wrapping form blocks 17 and 18. The operation of the carriage 31 is effected without lost motion inherent in mechanical drives and enables operation of the wrapping machine with a minimum of delay between dischange of the wrapped package and the receiving of the succeeding package and wrap. To insure proper operation of the limit switch 64 upon adjustment of the throw of the arm 40, the arm is provided with a contact element 70 to engage the switch 64. As shown in Fig. 1, the

to indicate the pressure of the contact element 70 is adjustable on the arm 40 as indicated at 71.

It should be noted that during the extension and retraction of the carriage 31, air is continuously exhausted through the exhaust conduit 61. According to the present invention, this air is employed to assist the travel of the wrap and box from the conveyor into position between the wrapping form blocks 17 and 18. As shown in Fig. 4, the exhaust conduit 61 is connected to a header 72 inter'mediate the conveyor and the wrapping machine and having a plurality of nozzles 73 opening into the area between the conveyor 10 and the wrapping machine 19 to provide a cushion of air upon which wrap W may travel. The cushion of air obviates the necessity for mechanical guides which are likely to interrupt the travel of the wrap and interfere with the operation of the wrapping machine.

While a particular embodiment of the present invention has been illustrated and described herein, it is not intended to limit the invention to such a disclosure, and changes and modifications may be incorporated and embodied therein within the scope of the following claims.

I claim:

1. For a package wrapping machine having wrapping form :blocks and means including a drive shaft for reciprocating said blocks from and to a package-receiving position, feed means comprising a carriage having packageengagirrg arms thereon normally positioned in registry with said blocks in the package-receiving position thereof, a framework including means slidably mounting said carriage for extension and return of the package-engaging arms from and to their normal position to an outer limit position to pick up a package and wrap, a carriage arm pivotally mounted at one end on said framework and pivotally mounting said carriage at the other end, a pneumatic cylinder, means mounting said cylinder on said framework, a double-acting reciprocating piston in said cylinder, means mounting the piston on said carriage arms to displace the same and effect extension and return of said package-engaging arms, pneumatic fluid supply and exhaust means for said cylinder including valve means operated by said drive shaft to effect reciprocation of said piston and displacement of said arms in timed relation to the reciprocation of the wrapping form blocks, a conduit connected to the pneumatic fluid exhaust means of said cylinder, and nozzle means in fluid communication with said conduit underlying the path of movement of said package-engaging arms, and operable upon operation of said piston to form a pneumatic fluid cushion partially supporting the packages and Wrap during return of said package-engaging arms to their normal position.

2. For a package wrapping machine having wrapping form blocks and means including a drive shaft for reciprocating said blocks from and to a package-receiving position, feed means comprising a carriage having packageengaging arms thereon normally positioned in registry with said blocks in the package-receiving position thereof, a framework including means slidably mounting said carriage for extension and return of the package-engaging arms from and to their normal position to an outer limit position to pick up a package and wrap, a carriage arm pivotally mounted at one end on said framework and pivotally mounting said carriage at the other end, an air cylinder, means mounting said cylinder on said framework, a double-acting reciprocating piston in said cylinder, means defining a longitudinal slot in said carriage arm between the center thereof and said one end thereof, a pivot pin on said piston adjustably mounted in said slot and mounting the piston on said carriage arm to displace the same and eifect extension and return of said packageengagin-g arms through a distance at least twice the throw of the piston in said cylinder, air supply and exhaust means for said cylinder including means operated by said drive shaft to efiect reciprocation of said piston and displacement of said arms in timed relation to the reciprocation of the wrapping form blocks, conduit means connected to the air exhaust means of said cylinder, and nozzle means in fluid communication with said conduit means underlying the path of movement of said packageengaging arms and operable upon operation of said piston to form an air cushion partially supporting the package and wrap during return of said package-engaging arms to their normal position.

3. Feed means according to claim 2 wherein said cylinder mounting means comprises an adjustable pivot on said framework to center said cylinder.

References Cited in the file of this patent UNITED STATES PATENTS 2,699,697 Kelso Jan. 18, 1955 2,757,586 Haessler Aug. 7, 1956 2,761,359 Sargent Sept. 4, 1956 2,781,136 Sehn et a1. Feb. 12, 1957 

